Internal-combustion engine



Nov. 5, 1929. E. P. DUMANOIS INTERNAL COMBUSTION ENGINE Filed June 1926 MINI!- I INVENTOQ K4 ATTY Patented Nov. 5, 1929 UNITED STATES PATENT OFFICE EMILE PAUL DUMANOIS, OF .BO'ULOGNE-SUR-SEINE, FRANCE, ASSIGNOR, BY MES NE ASSIGNMENTS, TO MAXMOOR CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE INTERNAL-COMBUSTION ENGINE Application filed June 3, 1926, Serial No. 113,392, and in France may 17, 1926.

It is well known that the volumetric compression in internal combustion engines is limited by the so-called detonation, which is caused by an actual explosive wave.

- However, in order to provide for a high to delay the formation of the explosive wave.

But in View of the fact that this wave is of both'a physical and a chemical nature, I have found that the desired result can be attained by merely physical methods and that antidetonating substances may be dispensed with.

My invention has accordingly for its object to provide means, acting in a physical ifnanner, for obviating such an explosive efect.

When an explosive wave proceeds through a conduit, it is well known that said wave may be readily stopped by simply increasing the cross-section of the conduit, the detonation being replaced by a regular combustion;

after a certain time, this may be followed anew by an explosive wave, if the section of the conduit remains constant or decreases.

It is further observed that, under similar conditions, an increase of the surface of the combustion chamber will produce a greater cooling of the gas, whereby the limit of compression at which the detonation takes place, as well as the limit of self-ignition by compression, will be set back.

With the above observations asa basis, 1 have been enabled to provide a combustion chamber by which the desired object is attained.

For this purpose, the cross section of the combustion chamber increases in the direction of propagation of the inflammation, and

the increase in the section may be continuous or intermittent; the surface of the walls is relatively large, so as'to obviate the explosive wave which tends to beproduced, or; to stop the propagation of such waves.

The appended drawing shows by way of example, various embodiments of ,theinvention.

VII of Fig. 6.

Figs. 1, 2 and 3 are respectivel sections on the line II of Fig. 2, IIII 0 Fig. 3, and a front view,'of the first embodiment, with the piston at the upper dead centre. Fig. 4 is a front view of a modification. Figs. 5 and 6 are vertical axial sections of further modifications. Fig. 7 is a section on the line VII- As shown in Figs. 1 to 4, theignitor is disposed at 1 in the cylinder 2, and, at its upper end, the piston is formed with a head-or projecting part 4, whose upper face comes near the cylinder head when the piston is at the upper dead centre, as shown in the drawing. The head is cut out to form a cylindrical recess6 through a suitable length, according to the direction of propagation of the inflammation. In the plane B-B, the offsets 7- causing an abrupt enlargement of the combustion chamber, both by the increase of cross section of the cylindrical recess and by the lowering of the level of the upper face of the Zhead 4;, which proceeds from 5 to 8. Likev variations in the section of the cylindrical recess and in the lowering of the level .of the upper face of the head 4 will take place in the planes of transverse ofisets 9, 10, 11 and vertical ofi'sets 12, 13, 14.:

The operation is as follows:

The inflammation begins at 1, and proceeds at a certain velocity the piston still raising, thus reducing the volume and facilitating the production of an explosive wave; when the inflammation attains a point near the section B-B,'however the section is"abruptly enlarged, causing an expansion by which the wave which might have been produced will be stopped. The same is true when the inflammation reaches the section -G"C, then the section D--D, and finally the section E-E.

From the foregoing itwi'll be seen that the different ofisets formed in the piston, start-- ing from the point of ignition will produce, as the inflammation attains the respective, offsets, suitable expansionswhich will pre-' CC, DD, E--E, by the formation tion in which the offsets at thetop of the pis- -ness, the term cylindrical to designate the outline of the successive recesses, but it should be noted that the invention is not restricted to cylindrical surfaces in the geometrical sense of the word, but relates to surfaces of a substantially cylindrical shape, or even to conical, spherical or like surfaces, provided that the cross-sections are progressively larger in 'the direction of propagation of the inflam-v mation.

Moreover, the term offset relates to regions of abrupt augmentation of the cross sec tion, but the walls may be either plane or curved, and suitably inclined and connected together.

The number of offsets may be increased at will, either upon the whole or upon a part of the piston surface, in the direction of propagation of the flame, the whole or a part of the offse s being thus replaced by a continuous surface such that the cross section is progressively larger.

In case the valves are'laterally disposed or with engines with sleeve valvesor engines of the tw -stroke type, the offsets or the surfaces connecting two successive sections of increas ing cross-section maybe provided solely upon the piston (as in the preceding case) or solely upon the end of the cylinder, orboth-upon the end of the cylinder and the end of the piston. In the preceding constructions. the'ignitor .lS situated upon the side wall of the cylinder. Arrangements based upon the same principle may be provided in case the-ignition deviceis mounted on the cylinder head, for instance at the centre thereof.

' Figs. 5 to 7 show, by way of example, a piston construction which may be employed in this case, the 'ignitor being situated at 20. The offsets now consist of circular or other Brojections and the planes B-B, (r-O,

- -D, E-E of Figs. 1 to fare replaced by the cfylindrical'or other sui'faces B C D E whic form the required ofl'sets' on the end of the piston. The operation is the same as before. By increasing the number of offsets upon the whole or a part of the piston surface, I may obtain; in the limit, a, piston surface WlllCll will be wholly or partially continuous,

- as above indicated.

.Whensidevalves are employed, or when tlie engine 1s of the sleevewalve or thetWo-fl ok type, the offsets, or surfaces connecting parts of increasing section, may be situated either on the end of the piston or on the end of the cylinder 15, or on the end of the piston and the end of the cylinder, as shown in F ig.. 6.

When the engine comprises several ignitors, the increase in the sections will take place (as above indicated) in the direction of propagation of the flame, starting from the different ignition points.

In the various embodiments hereinbefore described, I further obtain a material increase 'of the surface of the chamber in contact with the fuel mixture relatively to the constructions in currentuse, and hence an increased cooling of the gas, by which the risk of detonations and self-ignition by compression will be diminished.

Having now described my lnventlon, what I claim as new and desire to secure by Letters Patent is:

1. An internal combustion engine comprisjacent to the more constricted portion of said passage. V

2. An internal combustion engine comprising opposing portions in the combustion chamber thereof each having surfaces dis-v posed in offset relation, and forming a passage therebetween increasing in cross-section from the ignition point in the direction of propagation of the inflammation.

3; An internal combustion engine comprising opposing portions. of the combustion chamber, and ignition means disposed in said combustion chamber; certain of said portions including a step formation having certain of the surfaces thereof disposed transversely of the direction of propagation of the inflammation, and facing the portion of said combustion chamber remote from said ignition means. I

4. An internal combustion engine comprising opposing portions forming a combustion the enlarged portion of said combustion chamber. I

5. An internal combustion engine comprising a combustion chamber ceiling of step formation forming with an opposite portion of the combustion chamber a passage increasing in cross-section'from the ignition point in the direction of propagation of the inflammation.

6. An internal combustion engine-comprisstantially off-set relation to each other,

ingthe ceiling of the combustion chamber and a p1ston,.each having a plurality of surfaces disposed in offset relation to each other, and the same providing therebetween a passage increasing in cross-section by abrupt steps. I 7. An internal combustion engine comprismg a combustion chamber ceiling having surfaces of step formation forming a projection in spaced relation to the lateral wall portions of the combustion chamber and providing an ou wardly flaring recess about said projection.

' 8. An internal combustion engine comprising a portion of the ceiling of the combustion chamber having a recess about the spark plug provided with surfaces of step formation, and a piston having tion chamber, and provided with surfaces of step formation.

9. An internal combustion engine comprising a cylinder having a combustion chamber at the end thereof, and a piston in said combustion chamber; said piston and the ceiling of the combustion chamber including tapering portions of step formation projecting towards each other, and providing a space about the same increasing in cross-section outwardly therefrom.

10., An internal combustion engine comprising a portion of step formation having in exposed relation to the interior of the combustion chamber transversely extending step surfaces disposed in successive planes inv substantially off-set relation to each other and vertically extending riser surfaces connecting the step surfaces; the combustion chamber space contiguous to said step and riser surfaces abruptly varyingin cross-section in accordance with the variations in location of said step surfaces, and ignition means in said combustion chamber disposed to cause propagation of the through said space over said step and riser surfaces.'

11. An internal combustion engine comprising a portion of step formation projecting into the combustion chamber and having in exposed relation to the interior of the combustion chamber transversely extending step surfaces disposed in successive planes in subd an vertically extending riser surfaces connecting the step surfaces; the combustion chamber space contiguous to said step and riser surfaces varying in cross-section in accordance with the variations in location of said step surfaces, and

tion' chamber disposed to cause propagation of the inflammation therefrom'through said space over said several step and riser surfaces.

12. An internal combustion engine comprising a portion of step formation projecting into the combustion chamber thereof and having in exposed relation to the interior a projection into the combus-- inflammation therefrom ignition means in said combus-' of the combustion chamber transversely extending step surfaces disposed in successive planes in substantially off-set relation to each other and vertically extending riser surfaces connecting the step surfaces; the combustion chamber space contiguous to said step and riser surfaces progressively increasing in cross-section by abrupt steps, and ignition .means adjacent to the more constricted portion of said space for causing the inflammation to be propagated over said step and riser tions in. location of said step surfaces, and

ignition means in said combustion chamber disposed to cause the inflammation to be propagated therefrom through said space over said several step and riser surfaces.

14. An internal combustion engine comrising ignition means in the combustion c amber thereof, and a portion of step formation projecting into the combustion chamber in spaced relation to the lateral wall porber space contiguous to said step and riser surfaces increasing in cross-sectionin the direction of propagation of, the inflammation.

15. An internal combustion engine com?- prising a portion of step formation in the combustion chamber thereof; having in exposed relation to the interior of the combustion chamber transversely extending annular step surfaces disposed in successive planes in substantially off-set relation to each other and vertically extending riser surfaces connecting the step surfaces; and the combustion chamber space contiguous to said step and riser surfaces varying in crosssection by abrupt steps in accordance with the inflammation therefrom through said space over said several step and riser surfaces.

16. An internal combustion engine com- -13 prising a portion of step formation in the 'tions thereof; said projecting portion havsaid portion 4 ,the variations inlocation of said step surcombustion chamber thereof; said portion having in exposed relation to the interior of the combustion chamber transversely extending annular step surfaces disposed in suecessive planes in substantially off-set relation to each other and vertically extending riser surfaces connecting said step surfaces; and said step and riser surfaces providing a combustion chamber space increasing in cross-section by abrupt steps, andignition meanaadjacent to the more constricted portion of said combustion chamber.

17. An internal combustion chamber comprising a portion of step formation projecting into the combustion chamber thereof in spaced relation to the lateral wall portions thereof; said portion of step formation having in exposed relation to the interior of the ing in exposed relation to the interior of the combustion chamber transversely extending annular step surfaces disposed in successive planes in substantially ofi-set relation to each other and vertically extending riser surfacesconnecting the step surfaces; and said step and riser surfaces providing a combustion chamber space increasing in cross-section outwardly by abrupt steps, and ignition means disposed axially relative to said projecting portion. s

19. An internal combustion engine comprising a cylinder having a combustion cham-' ber at the end thereof, a piston in said cylinder, and a step formation on the head thereof having in exposed relation to the interior of the combustion chamber transversely'extendring step surfaces disposed in successive planes in substantially off-set relation to each other and vertically extending riser surfaces connecting said step surfaces; the combustion chamber space contiguous to said step and riser surfaces abruptly varying in cross-section in accordance with the variation in location of said step surfaces, and ignition means in said combustion chamber disposed to cause propagation of the inflammation therefrom through said space over said several step and riscrsurfaces.

20. An internal combustion engine comprising a cylinder having a combustion chamber at the end thereof, a piston in said cylinder, a'step portion on the head thereof having &

in exposed relation to the interior of the combustlon chamber transversely extendmg step surfaces disposed in successlve planes 1n sub stantially offset relation to each other and the relatively enlarged portion of said space.

21. An 'internal combustion engine comprising a cylinder having a combustion chamber at the end thereof, and a piston in said cylinder, a step portion on the head thereof 1ncreasing in height from the periphery towards the center of said piston head and projecting into said combustion chamber in spaced relation to the top and lateral wall portions thereof; said step formation including transverselyextending step surfaces disposed in successive planes in substantially offset relation to each other and Vertically extending riser surfaces connecting the step surfaces, and ignition means in said combustion chamber disposed to cause propagation of the inflammation therefrom over said several step and riser surfaces.

An internal combustion engine comprislng a cylinder having a. combustion chamber at the end thereof, a piston in said cylinder, and a step portion on the head thereof increasing in height from the periph-. ery towards the center and forming with the wall portions of said combustion chamber a space increasing in volume by abrupt steps from the axis of said cylinder outwardly, and ignition means disposed on the Wall of said combustion chamber axially of the cylinder adjacent to the more constricted portions of said space.

23. An internal combustion. engine comprising a cylinder having a combustion chamber at the end thereof, a piston in said cylinder, and a formation on the head thereof increasing in height from the periphery to- Wards the center and consisting of transversely extending step surfaces disposed in successive planes in substantially off-set relation toeach other and vertically extending riser surfaces; said step and riser surfaces and the opposing wall portions of said combustion chamber providing a space therebetween increasing in volume by abrupt steps from the axis'of said cylinder outwardly, and ignition means disposed on the wall of said combustion chamber axially of the cylinder adjacent to the more constricted portion of said space.

24. An internal combustion engine com prising a step formation on the ceiling of the combustion chamber having in exposed relation to the interior thereof transversely extending step surfaces disposed in successive planes in substantially off-set relation to each other and vertically extending riser surfaces connecting the step surfaces; the combustion chamber space contiguous to said step and riser surfaces abruptly varying in cross-section in accordance with the variation in location of said step surfaces, and ignition means in said combustion chamber disposed to cause propagation of the inflammation therefrom through said space over said several step and riser surfaces.

25. An internal combustion engine comprising a step formation on the ceiling of the combustion chamber having in exposed relation to the interior thereof transversely extending step surfaces disposed in successive planes in substantially off-set relation to each other and vertically extending riser surfaces connecting the step surfaces; the combustion chamber space contiguous to said step and riser surfaces abruptly increasing in crosssection, and ignition means disposed adjacent to' the more constricted portions of said space to cause propagation of the inflammation over said several step and riser surfaces towards the enlarged portion of said space.

26. An internal combustion engine comprising a step formation on the ceiling of the combustion chamber having transversely extending annular step surfaces disposed in successive planes in substantially off-set relation to each other and vertically extending riser surfaces connecting the step surfaces;

said step and riser surfaces being exposed to and forming a combustion chamber space increasing in cross-section by abrupt steps, and ignition means adjacent to the 'more constricted portion of-said space.

27. An internal combustion engine comprising a downwardly projecting step formain substantially off-set relation to each other and vertically extending riser surfaces connecting the step surfaces; the combustion chamber space conti uous to said step and riser surfaces abrupt y varying in cross-section in accordance with the variation in location of said step surfaces, and ignition means in said combustion chamber disposed to cause propagation of the inflammation therefrom through said space over said several step and riser surfaces. 29. An internal combustion engine comprising a downwardly projecting step formation on the ceiling of the combustion chamber having in exposed relation to the interior thereof transversely extending annular step surfaces dis osed in successive planes in substantially 0 -set relation to each other and vertically extending riser surfaces connecting the step surfaces; the combustion chamber space contiguous to said step and riser surfaces abruptly increasing in crosssection in accordance with the location of said step surfaces, and ignition means disposed adjacent to the more constricted portion of said space to cause propagation of the inflammation over said several step and riser surfaces towards the enlarged portion of said space.

Intestimony whereof I have signed my tion on the ceiling of the combustion chamber having in exposed relation to the interior thereof transversely extending step surfaces disposed in successive planes in substantially off-set relation to each other and vertically extending riser surfaces connecting the step surfaces; the combustion chamber s ace contiguous to said step and riser sur aces abruptly varying in cross-section in accordance with the variation in location of said. step surfaces, and ignition means in said combustion chamber disposed to cause propagation of the inflammation therefrom through said space over said several step and riser surfaces.

28. An internal combustion engine a step formation on the ceiling of the combustion chamber projecting downwardly in spaced relation to the lateral wall portions thereof and having in exposed relation to the in-' terior thereof transversely extending annular step surfaces disposed in successive planes 

